Manufacture of steel.



T. D. MACKIE & G. F. FORWOOD.

MANUFACTURE OF STEEL. APPLICATION FILED NOV,24,1911.

Patented Apr. 39, 19152.

4 BHEE'IE- SIikBT 1 T. D. MACKIE & G. P. FORWOOD. MANUFACTURE OF STEEL. APPLIUATION IILED NOV.24,19 11.

1,024,999. Patented Apr. 30, 1912.

4 SHEBTSSHEET 2v Fig.2

Inventors;

T. D. MAGKIB & G. F. PORWOOD.

MANUFACTURE OF STEEL. APPLIOATION TILED Nov. 24, 1911.

Patented Apr. 30, 1912.

=1 SHBETB SHEET 3v lhventors:

m0 1 w, 91!? W T. D. MACKIE & G. F. FORWOOD.

MANUFACTURE OF STEEL.

APPLICATION FILED NOV. m, 1911.

1,024,999. Patented Apr. 30, 1912.

4 BHEETS-BHBET 4.

Inventors:

Hi nesses:

ZMEM W.

UNITED sTATEs r rnnrr orr on.

TOM DABKE MACKIE, or BOWES PARK, AND GEORGE FREDERICK ronwoon, 0F

' LIMPSFI'ELD, ENGLAND.

MANUFACTURE OF STEEL.

Patented Apr. 30, 1912.

1,024,999, Specification of Letters Patent.

1 Application flied November 24, 1911. Serial No. 662200.

To all whom it may concern Be it known that we, TOM DARKE IVIACKIE, a subjectof the Kin of Great Britain and Ireland, and a resi ent of Southwood, Palmerston Road, Bowes Park, in the county of Middlesex, England, and Gnonon FREDERICK Fonwoon, a subject of the King of Great Britain and Ireland, and a resi dent of West Chart, Limpsfield, in the county of Surrey, England, have invented certain .new and useful Improvements in the Manufacture of Steel, of which the following is a specification.

This invention relates to the manufactureof steel by an expeditious process adapted for being carried out in a specialapparatns of the character hereinafter described, and is designed to insure the production of castings free from .imperfections of the kind commonly known as blowholes.

It is Well known that one of the ol'ijections to the employment of pneumatic )rocesses such for example as Bessemer s-for the production of steel castings, is that, during the removal of the nietalloids by oxidation with excess of air, there is a tendency for the iron to become oxidized, with the result that blowholes occur in the finished article.

According to our improved method of manufacture-particularly when the pro duction of steel castings is in view-the oxidized metal and slag from' the converter (which may be of any known type) are transferred to the hearth of a reverheratory furnace, and, after the removal of the slag. the metal is subjected to the action of a re-- ducing gas, such as hydrogen. blue watergas or the like, with the result that it he comes deoxidized. On reaching the upper portion of the furnace the reducing ,Qus meets with air, becomes ignited and burn with the effect that the metal is rxp asied to the heat generated by the combustion. but

is protected from its oxidizing influences;

; luaicli' roat-luul.

is a plan of the apparatus, Fig. i a longitudinal vertical section, and Fig. 5 a transverse vertical section on the line .1? a: Fig. :2.

According to our preferred method of construction, illustrated in the accoinpai'iying drawings, the converter a and reverberatory furnace b are parts of one and the same a1 paratus; but for convenience in nonstruction and for facilitating the repair of the linings or other parts, are made separable at the joints 15", The operation of trans ferring the metal from the converter [1 to the furnace b as elic t-ted by simply tilting the bi-part structure, the latter being. with this obyect, mounted on trunnions if, (I, carried in supports r. it will he soon that the convert r a is in direct commuuication with the revsrheralonv furnace Z and the latter with an exhi-ns on f win-n e twain-hes a flue y for i'zol'nfr ring the swiping; gnu-s to a rcgeneratiu' \tllvit they ..e wuploye l to! heatii'ig the :iiz hlasi hezrin aller r: d to.

The ron -mrirr turnhiuni wi h two twyers I: ll, whil n PM ital/om; tiun (Fig. 4-), air. ill'tl li li hot. i ao'uiilied ll'miugh iWjJ"? .5. mini iil' iil gas or equivalent gas through llu lvvyr-r it; the mixture bring: tired in the usual manner. The supply at air anal *5 is maintained until the entire u uiaratus has been thoroughly heated; whereupon the air and gas supplies are shut oil. the apparatus swung into a verti al iNmlilOIl (Fig. l) and a charge oi nuilten un'ztal is Zl il'lirie l from an ordinary cupole. The couw-i having been swung lo surli an angle as t enable the upon llie surface of the uulai. u :ilz si of hot air is admitleil through the over it or through both the tu ve if Ii and the oxidatum oi the impurities prover-1h in the usual Q manner. Jinx blowing of tin metal is not,

howev orried so far 11 in the Bessemer paw-es but {as in the; Huelieh nit-thud} un til the arming of silicon and manganese required in 1hr iiui luwd muimial is ::1un'().\'i 'iluw uiiilml lwiug now shut oil, the c-ouurr'lw is turned to a horizontal position. with the elte t that the metal and slug flow lulll the converter a. to the hearth J) of the rewrl zraiory furnace Z. The air and }1 l (lil:f1tl gas supplies to the twyers h h' are new again opened, and, owing to the h ated condition of the furnected to a regenerator by the addition of suitable material, the apnace,'ignition takes place; the air andproducer gas supplies being so adjusted as to produce a long flame over the surface of the metal on the hearth b of the reverberatory furnace b. The waste gases escape by way by of the fine 9 which latter is in communiea' 1); the joint.

tion with a main flue j (Fi g in the flue g'being struck rom the: center of the trunnions d d. The fine j isoonglot shown) provided with a chimney sha duce the necessary draft throng out the ap paratus. The charge on the hearth b is now treated with oxid of iron, in the usual manner, as in an open hearth furnace, and is brought down slightly below the percent-- age of metalloids required in the finished product. The slag having been thickened paratus is slightl .tilted on its trunnlo'ns with the object o facilitating the removalof the slag; it being important for the next stage of the process that the molten metal be left with a clean surface. tus having been restored to a horizontal position, the metal is exposed to a reducing atmosphere obtained by the employment of blue water-gas or the like, containing 50% hydrogen or thereabout; this deoxidiz ing gas being introduced through the twyer k arranged at a level slightly above the surface of the metal, while a suitably restricted air-supply enters through twyer is placed at a higher level. In the heated condition of the furnace, the gaseous mixture i nites at the top of the furnace, where the air enters; thus maintaining, by radiation, the temperature of the bath; while the metal on the hearth at the bottom of the furnace is subjected to the reducing actionof the gas entering the furnace by Way of the lower twyer is before referred to.

It will be perceived that, under conditions such as those described, although an oxidizing atmosphere exists in the upper portion of the furnace, a stream of deoxidizmg gas impinges upon and bathes the surface of the metal, thusmaintaining a deoxidizing atmosphere in the. neighborhood thereof. Such oxygen as may be present in the metal having, by these means, been removed and the usual additions of carbon, manganese, silicon or other metals or metalloids, made, the charge is ready for pouring, and may ada ted to pro.-.

twyer-boxes being connected by The apparaforthwith" be'used for the production of castings.

The combined converter and reverberw tory fu naceis rotated on its trunnions d d means of a worm l and worm-wheel Z.

the hot-blast conduit leading to the twyer-box h and having branches m for supplying the twyer-box h, and m m for supplying the twyer-boxes ll: 11:. n is the mainfor supplying the tw er-box h with producer gas, or the twyerres k! is with blue water-gas, according to the stage of the process in operation; the last mentioned means of flexible pipesin order that the twyers k k may if desired be removed during the conversion' stage; dummy plugs'being substituted in their laces.

0 is a hinged sion p 15 a hood for collectin and: conveying awa the waste ga es whic escape during the initial stages-o the process.

What we claim as our invention and desire to secure by Letters Patent is:-

1. The process for the conversion of iron into steel which consists in treating the charge on the hearth of a furnace with ox id of iron removing the slag from said charge, then blowing the charge with a reducing gas in order to deoxidize the same while a gaseous mixture in a state of combustion is maintained exclusively in the upper portion' of the furnace.

2. In the process for the conversion of iron into steel, the ste s which consist in maintainin a supply 0 deoxidizin gas in contact wit a surface of the meta and a suitably restricted supply of a combustion supporting gas in the up er portion of the furnace out of contact with the metal, the former servin to protect the metal from oxidation, an ultimately on reaching the upper portion of the furnace, mingling with the combustion supporting as and there burning, substantia ly as set orth.

In testimony whereof we have signed our names to this specification in the presence of two subscribing witnesses.

' TOM DARKE MAOKIE. crease FREDERICK roawoon.

Witnesses:

O. J. WORTH, C. P. LIDDON.

door for closingthe exten- 

